1. A method of scrubbing a gas stream with re-circulated kiln dust, comprising:
providing a source of kiln dust;
forming a sorbent for gas scrubbing including:
hydrating said dust to form hydrated lime to form said sorbent;
re-circulating collected kiln dust;
mixing said collected kiln dust with said hydrated lime sorbent;
conditioning said sorbent with water to optimize scrubbing temperature; and
contacting said sorbent with said gas stream to be scrubbed.
2. The method as set forth in claim 1, wherein said method is a semi-dry method.
3. The method as set forth in claim 1, wherein said conditioning includes at least one unit operation selected from the group consisting of flash drying, pulverizing, and classifying.
4. The method as set forth in claim 1, wherein conditioned sorbent is contacted by said gas to be scrubbed by forced circulation.
5. The method as set forth in claim 1, further including the step of controlling the temperature at which said scrubbing occurs.
6. The method as set forth in claim 5, wherein said temperature is controlled by adjusting water volume in said sorbent.
7. The method as set forth in claim 6, wherein said temperature is controlled by water injection in a reactor within which said gas is scrubbed.
8. The method as set forth in claim 1, further including the step of flash drying said sorbent.
9. A scrubbing process for flue gas generated in a lime synthesis plant having kilns for calcining limestone, comprising:
hydrating lime kiln dust to capture residual free lime present in said dust;
contacting, hydrated lime with a flue gas stream generated from said kilns for a period sufficient for reaction with pollutants present in said flue gas; and
re-circulating collected non-hydrated lime kiln dust for mixture with hydrated lime kiln dust sorbent for contact and reaction with said flue gas, whereby said sorbent is replenished in the absence of extraneous sorbent injection.
10. The method as set forth in claim 9, wherein said process is self-sustaining.
11. The method as set forth in claim 9, wherein said hydrated lime is conditioned prior to contact with said flue gas.
12. The method as set forth in claim 11, wherein conditioning of said hydrated lime includes a unit operation selected from the group consisting of flash drying, pulverizing, and classifying.
13. The method as set forth in claim 11, wherein said sorbent is pneumatically conveyed for contact with said flue gas.
14. The method as set forth in claim 11, wherein said sorbent is mechanically conveyed for contact with said flue gas.
15. The method as set forth in claim 11, wherein said method is conducted in an air lock.
16. The method as set forth in claim 9, further including the step of repeatedly re-circulating sorbent for maximizing the efficiency of said process.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An ice cream freezer comprising a frame with a freezer pipe mounted thereon, a cooling system, an introducing pipe system with an introducing pump, valves for introducing ingredients to the freezer pipe, a removing pipe system with removing pump for removing finished ice cream from the freezer pipe, motors for driving the freezer pipe and the pumps and a plurality of indicators for recording different parameters, wherein the freezer pipe is disposed at a lowest point of the freezer and wherein the cooling system is disposed proximal the freezer pipe, the frame comprising coverings, an upper part of the coverings being openable or removable, and the coverings comprising an upper closable box containing motors, valves and other sensitive components.
2. The ice cream freezer of claim 1, further comprising introducing pipe system and removing pipes disposed on a same end of the frame, and wherein the cooling system is disposed at an opposite end of the frame.
3. The ice cream freezer of claim 2, wherein the introducing pipe system and the indicators are mounted above or beside the freezer pipe.
4. The ice cream freezer of claim 1, wherein at least a part the coverings are transparent.
5. The ice cream freezer of claim 1, wherein the coverings only cover a part of the frame situated above the freezer pipe.
6. The ice cream freezer of claim 1, wherein the parameters include pressure, temperatures flow, and combinations thereof.
7. An ice cream freezer comprising a frame, a freezer pipe mounted thereon and disposed at a lowest point of the freezer, a cooling system proximal the freezer pipe, an introducing pipe system with an introducing pump, valves for introducing ingredients in the freezer pipe, a removing pipe system with removing pump for removing finished ice cream from the freezer pipe, motors for driving the freezer pipe and the pumps, a plurality of indicators for recording different parameters, the introducing pipe system and the removing pipes being disposed on one end of the frame and the cooling system being disposed on another end of the frame, further comprising coverings on the frame having upper portions, wherein the coverings comprise an upper closable box containing motors, valves and other sensitive components.
8. The ice cream freezer of claim 7, wherein the introducing pipe system and the indicators are mounted above or beside the freezer pipe.
9. The ice cream freezer of claim 7, wherein the parameters are selected from the group including of pressure, temperature, flow, and combinations thereof.
10. The ice cream freezer of claim 7, wherein the upper portions form an opening.
11. The ice cream freezer of claim 7, wherein the upper portions are removable.
12. The ice cream freezer of claim 7, wherein at least a part the coverings are transparent.
13. The ice cream freezer of claim 7, wherein the coverings only cover a part of the frame situated above the freezer pipe.